What are LED advantages and disadvantages?

Answer 1

Advantages - efficacy, they produce more light per watt verse a regular bulb. Disadvantage - cost, for reasons why they are better, they cost more.

Color is much crisper and emits less energy to project although the work best in a temperature controlled environment so if the temperature fluctuates then the life of the bulb is lessened.

LED doesn't contain Mercury which is a toxic substance used in fluorescent lamps. Although the blue light LED's emit can cause light pollution and even possibly cause eye damage.